Bicycles are a common transportation means. However, as times change, bicycles have also become a recreational means in the lives of modern people. Bicycle riding allows one to not only appreciate sceneries along the road while riding but also achieve the goal of working out for fitness, and is extensively loved by the public. However, not all occasions and climates (e.g., in the snow or rain) are suitable for bicycle riding. Thus, in order to enjoy the fun of bicycle riding under all circumstances, bicycle trainers have been developed. By securing and positioning one's bicycle on a bicycle trainer, one can stay amused with the fun of bicycle riding, disregarding space and location issues.
To better simulate actual riding conditions, a mechanical mechanism that changes the resistance along with speed is further disposed in certain bicycle trainers. The curve of the resistance may be set and adjusted according to a predetermined application scenario. However, such design only provides one single application scenario, and the amount of the resistance cannot be controlled as desired or be programmable.
Thus, a device with electrically controlled resistance is further designed. For example, the U.S. Patent Publication No. 20140171272, “Bicycle Trainer”, includes a frame assembly and a flywheel assembly. The frame assembly is for supporting the flywheel assembly. The flywheel assembly includes a flywheel axle, T-shaped portions disposed annularly around the flywheel assembly, and a flywheel member connected to the flywheel axle. The T-shaped portions receive a current to generate a magnetic field. When the flywheel axle drives the flywheel member to rotate, the flywheel member rotates against the magnetic field and thus provides a braking force. The strength of the magnetic field can be varied by changing the current, and the amount of braking force can be changed to simulate different scenarios.
However, the above braking force consumes a substantial amount of electric power. Thus, current bicycle trainers can only achieve full operations and functions given that they are connected to an external power supply, meaning that current bicycle trainers are nonetheless bound by an application location restriction.